Sonic depth indicator apparatus



Sept. 12, 1939, J, M MCSPADDEN 2,172,395

SONIC DEPTH INDICATOR APPARATUS Filed Feb. 28, 1958 FROM TRANCEIVR 42 AMPLIFIER INVENTOR JOSEPH M. MQSPADDEN ATTORNEY Patented Sept. 12, 1939 UNITED STATES PATENT- OFFICE 2,172,395 SONIC DEPTH INDICATOR APPARATUS Joseph M. McSpadden, United States Navy Application February 28, 1938, Serial No. 193,020

Claims. (Cl. 250-27) (Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) This invention relates to means for ascertainfrom shaft 9 and are respectively connected to ing depths and distances by sonic waves and more the deflecting plates l6, I1, is and is of rn g particularly to those portions of such apparatus ray tube 29,

as are immediately concerned with producing the The deflecting plates l6 and I1 constitute one 5 indication of the time at which the sonic wave is pair and the plates l8 and I9 constitute another i sent out and when the echo thereof returns. P functioning n a manner well-known in this Among the several objects of this invention art. It will be observed that the plates in each are: pair are connected to contact arms that are dis- To provide means for producing a rectangular pos d diametrically opposite each other. That is,

in trace on a cathode tube screen; the arms I2 and I3, respectively connected to I To provide means whereby the voltage drop, plates l6 and I! are disposed on a diameter, and across one portion of a direct current circuit may t r ght angles thereto, arms l4 and I5 likewise be varied in response to the received energy of lie on a diameter. Thus, each contact arm is the Sound echo; spaced 90 from the arms adjacent thereto. The

To simplify and generally improve the apparesult is that the rotation of the contact arms 1 ratus immediately concerned with the indication by shaft 9 will vary the resistance between each of t received h arm and the points of connection of annular rethe drawing: sistance i into the direct current circuit and each Fig. 1 is a schematic circuit diagram of the pair of arms will-produce an alternating voltage present invention; Wave such as 28 and 22 in Fig. 3, wherein it is 2 Fig. 2 is an end view of the cathode-ray tube seen that each wave is of substantially triangular showing the form of the trace thereon and the form. The resultant deflection of the electron indication of t received h stream in the cathode ray tube 20 gives a square Fig. 3 shows the form of the alternating voltage pattern. The contact arms E2 to Iii are connected as wave applied to the deflecting plates of the cathto the respective conductive leads to the deflecode ray tube. tion plates by slip rings, but for the purpose of The determination of depths or distances by Simplifying the drawing s as not been shown the sonic wave method requires apparatus for but instead a legend indicates the lead to which transmitting a sonic wave associated with means each arm is respect ve y connected.

to for indicating the time at which the transmitted A gaseous discharge tube 24 has its cathode 25 3 signal is sent and also means for receiving th connected to the low potential end of resistor 6 echo of the signal and indicating the lapse of time and t P te 25 ected to resistor 6 at such between the transmission of the signal and the point a to e the desired P e t d fference receipt of the echo. This invention is not conween ca d 5 d P e pacitor 21 cerned with the means for amplifying the signal is connected in parallel with resistor 6 between 3 energy to be transmitted, nor with the converting cathode 25 and P e 6- Resistor 28 is connected apparatus whereby the electrical energy is between the terminals of battery'29 and also, at changed into the mechanical energy of sound, no! One to t ode 5- A movable contact 30 with the mechanism for translating the sound on resistor 28 is connected through a resistor 3t energy of the echo into electrical energy, since to control grid 32 of the tube 24 to bias grid 32 41 such means are well-known and, inasmuch as normally egat ve w t r spect to cathode 25 and they constitute no part of the present invention, across the terminals of resistor 3| are connected they are not shown in the drawing. the leads 33 that carry the voltage set up in the Fig. 1 depicts a direct current circuit compristransceiver and amplifier y the rec ived echo as 5 ing leads 8 and 5 with the resistor 6 and annular is well known in this art similar to the leads 29 resistor I connected in series with the source of and 30 shown in Fig. 1 of the patent to Hayes direct current potential between the, adjacent 89- h as v s pr ss d upon terminal of 4 and 5,the annular resistor being the electrodes of tube 24 are such that the tube connected into the circuit at diametrically opp'ois normally non-conducting and during this time site points. Motor 8 drives shaft 9 upon which e Capac r 1 5 c ged to a potential deter- 64 is a cam It! to close switch ll periodically to send mined by the portion of resistor 6 connected in out a signal to the sound transmitting and reparallel therewith. However, when signal is receiving device, usually termed a transceiver. Also ceived the chang in p t al on the grid 32 is mounted on shaft 9 are four contact arms l2, 13, Such as to cause the tube 2 3 to become conduct- It and it that are insulated from each other and i g and during suc t the Potential p 61 across the portion of resistor 6 connected in parallel with the tube will be the same as the drop across the tube, which is normally between 12 and 18 volts. The diminution in drop across resistor 6 will have the effect of increasing the drop through annular resistor 1 and will therefore result inthe application of an instantaneous voltage of higher value to the deflecting plates of the cathode-ray tube 20, causing a displacement of the trace 23 as shown at 34 in Fig. 2, thus indicating the receipt of the echo from the signal. The drop across resistor 6 and across annular resistor I is preferably substantially equal normally, that is, in the example given about 55 volts. The duration of the time of discharge of tube 24 is determined by the capacitance of capacitor 21, since when capacitor 21 is discharged the positive. bias on cathode 25 from battery 29 is sufficiently great to extinguish tube 24.

The indication in Fig. 2 is based upon the conditions that shaft 9 makes one revolution per second and that the sound wave has travelled 1500 feet before reflection, making the total path of the signal and its echo equal to 3000 feet. The velocity of transmission of sound in water being approximately 4800 feet per second, the interval between the transmission of the signal and the reception of the echo is flve-eighths second. Since the cam I is so related to the arm 12 that the signal is sent when arms I! and I3 are directly in contact with the lines in the direct circuit feeding into resistor 1, the above time values would produce an indication of the echo at 225, as shown.

The invention herein described and claimed may be used and/or manufactured by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

I claim:

1. Apparatus of the class described, comprising a source of direct current, an annular resistor connected at one point to one sideof said source, a second resistor connected in series between the other side of said source and a point on said annular resistor diametrically opposite the aforesaid point; a gas-filled discharge tube having an anode, a cathode and a control'electrode with said anode and said cathode connected to spaced points on said second resistor to reduce the potential drop between said spaced points on said second resistor to a value equal to the drop through said tube when said tube passes current; a capacitor connected between said anode and said cathode to maintain said tube conducting for a predetermined time, a source of direct current potential, 2. potentiometer resistor connected in parallel with said source and having one terminal connected to said cathode, a conductive lead connected to said control electrode, a second conductive lead variably connected to said poten tiometer resistor, a resistor connected across said leads adjacent said tube, a rotatable shaft, four radial contactor arms insulatingly fixed on said shaft at ninety degree intervals and contacting said annular resistor, an electrical conductor ope'ratively connected to each of said arms respectively, and a cathode ray tube having two pairs of deflecting plates, each of said plates being connected to one of said conductors, the conductors to which the plates of each said pair are connected being connected respectively to contact arms that are diametrically opposite each other.

2. Apparatus of the class described, comprising a source of direct current, an annular resistor vice to hold said device non-conducting until said a predetermined potential is applied, a' rotatable shaft, four radial contactor arms insulatingly fixed on said shaft at ninety degree intervals and contacting said annular resistor, an electrical conductor operatively connected to each of said arms respectively; a cathode ray tube having two pairs of deflecting plates, each of said plates being connected to one of said conductors, the conductors to which the plates of each said pair are connected being connected respectively to contact arms that are diametrically opposite each other, and means operative to impress upon said device a received voltage to render said device conductive.

3. Apparatus of the class described, comprising a source of direct current, an annular resistor connected at one point to one side of said source, a second resistor connected in series between the other side of said source and a point on said annular resistor diametrically opposite the aforesaid point, an ionizing discharge device that is rendered conductive when a predetermined potential is applied thereto and means to control the time of discharge thereof both connected in shunt between spaced points on said second resistance; adjustable biasing means for said device to hold said device non-conducting until said predetermined potential is applied, a rotatable shaft, four radial contactor arms insulatingly fixed on said shaft at ninety degree intervals and contacting said annular resistor, an electrical conductor operatively connected to each of said arms respectively, a cathode ray tube having two pairs of deflecting plates, each of said plates being connected to one of said conductors, the conductors to which the plates of each said pair are connected being connected respectively to contact arms that are diametrically opposite each other, and means responsive to a received voltage impulse to apply said predetermined potential to said tube and cause said tube to pass current whereby to decrease the poten tial drop across said second resistor and thereby to increase the drop across said annular resistor.

4. Apparatus of the class described, comprising a source of direct current, an annular resistor connected at one point to one side of said source,

a second resistor connected in series between the other side of said source and a point on said annular resistor diametrically opposite the aforesaid point, a rotatable shaft, four radial contactor arms insulatingly fixed on said shaft at ninety degree intervals and contacting said annular resistor, an electrical conductor operatively connected to each of said arms respectively, a cathode ray tube having two pairs of deflecting plates, each of said plates being connected to one of said conductors, the conductors to which the plates of each said pair are connected being connected respectively to contact arms that are diametrically opposite each other, and means responsive to a received voltage impulse to decrease the potential drop between the terminals of said second resistor due to current from said source ll thereby to increase the drop across said annular resistor due to current from said source.

5. Apparatus of the class described, comprising a source of direct current, an annular resistor connected to opposite sides of said source at respective diametrically opposite points on said resistor, a rotatable shaft, tour radial contactor arms insulatingly fixed on said shaft at ninety degree intervals and contacting said annular resistor, an electrical conductor operatively connected to each of said arms respectively, a cathode ray tube having two pairs of deflecting plates, each of said plates being connected to one of said conductors, the conductors to which the plates of each said pair are connected being connected respectively to contact arms that are diametrically opposite each other, and means responsive to a received voltage impulse to increase the potential drop across said annular resistor due to current from said source.

JOSEPH M. McSPADDEN. 

